I am coining a phrase: Cube-Jack

Cube-jack:  An event that takes place when a co-worker visiting me in my cubicle is approached by another co-worker, who then begins a conversation about something unrelated to my work but remains in my workspace.

A fairly extensive Google search turns up no uses of this term, so I'm coining it.  There you go.  Use it as a noun, verb, adjective...cubejack, cubejacking, cubejacker, cubejacked!